Steve
Looking at your most recent posting, it puts your original question in slightly different light. I think you need to look at things like
- preflight requirements - I think a PT helo needs a preflight once per flight and a Priv one once per day - or some difference like that
- engineering rules - if you take a door off a PT helicopter to fly without it in the summer (two split pins on a robbo, hardly rocket science) then I believe you have to have a licenced engineer replace the door!!! That rule does not apply on a Priv helo.
Uh oh, another CAA minefield...